1. Technical Field
The disclosure relates to a test device of a chip, and more particularly, to a test device for a magnetic stripe decoder chip.
2. Related Art
FIG. 1 is a relation diagram of a magnetic stripe and a decoding signal in the prior art. Generally, for a magnetic stripe 101a on a financial card or a credit card, specifically coded binary data is corresponding to a sorting and distribution situation of magnetic poles on the magnetic stripe. The magnetic stripe may record information using coding techniques such as a frequency modulation (FM) technique, a phase modulation (PM) technique, and a dual-frequency coherent phase (F/2F, or Aiken Biphase), technique. The drawing shows an example of distribution of magnetic poles coded by using the dual-frequency coherent phase coding technique (F/2F, or Aiken Biphase). A magnetic code electrical signal 102a is generated by sensing the distribution of the magnetic poles on the magnetic stripe 101a (including a plurality of magnetic north poles N and a plurality of magnetic south poles S).
As shown in FIG. 1, an F/2F coded signal 103a is a clock signal with high and low levels staggered, and is defined to 0 or 1 through duration of the high level or the low level. Consequently, the F/2F coded signal 103a may be decoded into a binary data sequence 104a according to various peak-to-peak periods T of the magnetic code electrical signal 102a. 
FIG. 2 is a schematic diagram of a magnetic stripe reading circuit 110a of the prior art. As shown in FIG. 2, a magnetic head 111a may sense movement of a magnetic stripe on a magnetic card, so as to generate the magnetic code electrical signal 102a shown in FIG. 1. A signal processing circuit 112a converts the magnetic code electrical signal 102a into an F/2F coded signal 113a. A decoder chip 114a receives the F/2F coded signal 113a, and performs decoding to obtain the binary data sequence 104a shown in FIG. 1.
As shown in FIG. 2, a front end of the signal processing circuit 112a is a differential amplifier, for receiving a differential signal (the magnetic code electrical signal 102a), output by the magnetic head 111a, and amplifying the signal, so that a comparator at a rear end detects a waveform to extract peaks by using a level voltage Vbias as a reference, thereby converting the peaks into the F/2F coded signal 113a. 
However, a manufacturer of the decoder chip 114a must detect the quality of the decoder chip 114a before delivery. In a current test manner, architecture of the magnetic stripe reading circuit 110a is adopted as a test circuit, and the decoder chip 114a is tested by swiping the card manually, so as to determine whether the decoder chip 114a can read information recorded by the magnetic stripe correctly.
However, the test method has the following problems:
1. In order to test the reliability of the decoder chip 114a, the same decoder chip 114a should be tested repeatedly using different swiping rates and different swiping directions, which is not only time consuming, but also has a low test speed.
2. Manually controlled swiping cannot maintain an accurate swiping rate; consequently, test conditions are inconsistent with actual operation, and test results are incomplete.